/*
 * SPDX-License-Identifier: Apache-2.0
 *
 * The OpenSearch Contributors require contributions made to
 * this file be licensed under the Apache-2.0 license or a
 * compatible open source license.
 */

/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/*
 * Modifications Copyright OpenSearch Contributors. See
 * GitHub history for details.
 */

package org.opensearch.search.aggregations.metrics;

import org.opensearch.index.query.QueryShardContext;
import org.opensearch.search.DocValueFormat;
import org.opensearch.search.aggregations.Aggregator;
import org.opensearch.search.aggregations.AggregatorFactories;
import org.opensearch.search.aggregations.AggregatorFactory;
import org.opensearch.search.aggregations.CardinalityUpperBound;
import org.opensearch.search.aggregations.support.MultiValuesSource;
import org.opensearch.search.aggregations.support.MultiValuesSourceAggregatorFactory;
import org.opensearch.search.aggregations.support.ValuesSourceConfig;
import org.opensearch.search.internal.SearchContext;

import java.io.IOException;
import java.util.Map;

import static org.opensearch.search.aggregations.metrics.WeightedAvgAggregationBuilder.VALUE_FIELD;

/**
 * Aggregation Factory for weighted_avg agg
 *
 * @opensearch.internal
 */
class WeightedAvgAggregatorFactory extends MultiValuesSourceAggregatorFactory {

    WeightedAvgAggregatorFactory(
        String name,
        Map<String, ValuesSourceConfig> configs,
        DocValueFormat format,
        QueryShardContext queryShardContext,
        AggregatorFactory parent,
        AggregatorFactories.Builder subFactoriesBuilder,
        Map<String, Object> metadata
    ) throws IOException {
        super(name, configs, format, queryShardContext, parent, subFactoriesBuilder, metadata);
    }

    @Override
    protected Aggregator createUnmapped(SearchContext searchContext, Aggregator parent, Map<String, Object> metadata) throws IOException {
        return new WeightedAvgAggregator(name, null, format, searchContext, parent, metadata);
    }

    @Override
    protected Aggregator doCreateInternal(
        SearchContext searchContext,
        Map<String, ValuesSourceConfig> configs,
        DocValueFormat format,
        Aggregator parent,
        CardinalityUpperBound cardinality,
        Map<String, Object> metadata
    ) throws IOException {
        MultiValuesSource.NumericMultiValuesSource numericMultiVS = new MultiValuesSource.NumericMultiValuesSource(
            configs,
            queryShardContext
        );
        if (numericMultiVS.areValuesSourcesEmpty()) {
            return createUnmapped(searchContext, parent, metadata);
        }
        return new WeightedAvgAggregator(name, numericMultiVS, format, searchContext, parent, metadata);
    }

    @Override
    public String getStatsSubtype() {
        return configs.get(VALUE_FIELD.getPreferredName()).valueSourceType().typeName();
    }
}
